Drawing units are inches, scale is 1:1. I use print preview, and click the button to center the image, but not "fit to page". I also normally toggle the black/white mode to black, but have tried both ways.

The PDF is still coming out blank. An oddity is that the Adobe Reader automatically scales the blank page to 2041% when it tries to display the file.

The SVG file comes out looking correct, but at an unknown scale. I have tried scaling by the standard 90 px per inch, but this makes the image too big by almost a factor of 2. By experimentation, it seems that scaling the drawing by around 2.5 results in something "close".

I am trying to use the SVG files as input to Ponoko.com's CNC laser cutter, so I need to know the exact scale factor.

The SVG output scale is indeed arbitrary. QCAD calculates the borders of the drawing and then performs an auto zoom of the drawing into these borders. Margins are applied to make sure that thick lines are not cut off at the borders.

Please note that QCAD SVG export is intended for presentation purposes only, not for further processing. Dashed lines are ripped apart, text is broken up, dimension entities are exported as lines and other shapes, etc.

To transfer geometry across to another program, the DXF format should be used instead.

QCAD 3 improves these aspects of SVG export with two options (preserve looks or preserve geometry) and the scale should be correct in the output in any case. Feel free to send us a drawing of yours, so we can convert it using QCAD 3.

Thanks, Andrew. Having this information will help me work around the scaling issues.

For now, I am drawing a large bounding rectangle around my piece drawings and then performing SVG scaling based on the known dimensions of the rectangle. I look forward to the new capabilities in version 3.

I believe that SVG is a very poor choice of formats for CNC control, but there are many other things I like about the service provider